1. Field of the Invention
The present invention relates generally to imprinting apparatuses which form patterns on objective materials, such as wafers and substrates, and more particularly, to an imprinting apparatus, in which a plurality of imprinting modules each having a pattern are separably coupled to each other to control a range of imprinting the patterns on an upper surface of an objective material according to an area of the upper surface of the objective material, and an actuator of each of the plurality of imprinting modules is independently self-aligned in response to surface conditions of the objective material to compensate for a relative pose error of a mold of each of the imprinting modules with respect to the objective material while each of the actuators is independently actuated by a controller, so that a pattern formed on each of the molds is accurately imprinted on the upper surface of the objective material, thus reducing the number of defective products.
2. Description of the Related Art
Generally, patterns, such as high density integrate circuits, are formed on upper surfaces of semiconductor wafers or substrates by imprinting apparatuses. That is, molds of the conventional imprinting apparatuses compress photosensitive materials, which are previously applied on the upper surfaces of objective materials, such as the semiconductor wafers or the substrates, so that the patterns of the molds are imprinted to the photosensitive materials on the objective materials.
There are two methods of forming the patterns on the objective materials using the conventional imprinting apparatuses. As shown in FIG. 1, the first is a method in which only one actuator with a single mold 1 is repeatedly and vertically actuated to imprint a pattern 2 of the mold 1 on an objective material W. Thus, the pattern 2 is repeatedly imprinted on each of a plurality of portions of an upper surface of the objective material W according to an imprinting sequence designated by the reference numerals 1 through 37, as shown in FIG. 3. The second is a method in which a plurality of patterns 4 are formed on a lower surface of a mold 3, as shown in FIG. 2, so that the plurality of patterns 4 are simultaneously imprinted on the objective material W at one time, as shown in FIG. 4.
However, in the first method in which the actuator with the single mold 1 is repeatedly and vertically actuated to imprint the patterns 2 on the objective material W, as shown in FIG. 1, a required imprinting time is increased in proposition to an increase in an area of imprinting the patterns on the objective material W. Furthermore, because the single mold 1 repeatedly imprints the same pattern 2 on each of the plurality of portions of the objective material W, accuracy of a conventional imprinting apparatus using the first method is reduces in response to increases in the number of repeated imprinting processes. Thus, the desired patterns may not be imprinted on the objective material W by deformation of the pattern 2 of the mold 1.
In addition, the conventional imprinting apparatus using the first method cannot be used in case that patterns of various types must be imprinted on the objective material W.
In the second method in which the patterns 4 on the mold 3 are imprinted on the objective material W at one time, when the upper surface of the objective material W is not leveled, the patterns 4 are not evenly imprinted. Thus, a defective product may result.
Typically, the objective material W, on which the patterns are imprinted, is supported on a vacuum chuck 5 by an absorption method. At this time, a predetermined portion of the objective material W, to which the absorption operation of the vacuum chuck 5 is practically executed, is slightly depressed in comparison with other portions of the objective material W. When the depressed portion of the objective material W is measured in a nano-scaled measurement, the upper surface of the depressed portion of the objective material W is curved, as shown in FIGS. 1 and 2. Therefore, in the conventional imprinting apparatus using the second imprinting method, the patterns formed on the mold 3 may not be evenly imprinted on the objective material W with the depressed portion, thus increasing the numbers of defective products.
Furthermore, because the mold 3 of the conventional imprinting apparatus using the second method has a larger imprinting area, air is not efficiently removed from a gap defined between the mold 3 and the objective material W while the patterns 4 of the mold 3 are imprinted on the objective material W. Therefore, the conventional imprinting apparatus using the second method is problematic in that a plurality of air pockets are undesirably generated on the imprinted surface of the objective material W, thus causing defective products.
As described above, the methods of imprinting the patterns on the objective material using the conventional imprinting apparatuses are limited in the two methods of repeatedly imprinting the single pattern or imprinting the patterns using the single mold 3 with the larger area at one time. Therefore, in case that the range of imprinting the patterns is changed, conventional imprinting apparatuses must change existing imprinting processes into new imprinting processes according to the range of imprinting the patterns. Otherwise, it may be impossible to use the conventional imprinting apparatuses in the different imprinting processes.